Building product and method of making the same



T. ROBINSON Aug. 15, 1933.

BUILDING PRODUCT AND METHOD OF MAKING THE SAME 2 Sheets-Sheet l rnillllnlllllllllllllt! x n 1 |\|I Original Filed July lO, 1928 INV TOR Y had ATTORN EYS Aug. 15, 1933. -r RQBlNSON 1,922,501

BUILDING PRODUCT AND METHOD OF MAKING THE SAME Original Filed July l0, 1928 2 Sheets-Sheet ATTORNEY ,-1 cheaply and uniformly.

Patented Aug. 15, 1933 UNITED STATES- PATENT OFFICE BUILDING PRDUCT AND METHOD 0F MAKING THE SAME Original application July 10, 1928, Serial No.

291,638. Divided and this application e ber 23, 1929. Serial No. 409,300

23 Claims.

This invention relates to roofing elements and is concerned more particularly with a novel shingle which is of great durability and resistance to the action of the elements, andto a method by which such products can be produced rapidly,

' such tapered construction, the new shingles may Ahavea substantial thickness at the butt so that they cast a considerable shadow and thus produce a roof of attractive appearance, and at the same time may be laid in overlapping courses with the shingles in the several courses lying fiat without buiging orbeing bent. I L

The new shingles are composed primarily of fibrous material bound together by a plastic substance capable of hardening, and preferably consist of a plurality of layers of such ingredients, differing among themselves in the relative proportions of fibre and plastic present but produced in such manner that the several layers are combined into a unitary structure. Because of the variations in the amounts of fibre present in the various layers, the layers differ in physical characteristics and I take advantage of these differ'- ences in the production of products for different uses. Y The fibrous materials used are of a wide variety and include, for example, asbestos, vegetable fibre, such as 'cocoanut fibre, wool felt scrap, bagasse and the like, with'which in some instances may be mixed suitable amounts of a filler such as clay. chopped hay may also be employed. The plastic substance that, I employ-is one capable of resisting the action of the weather, and I, have found that bituminous products, such as asphalt of a melt point capable of withstanding solar heat, is satisfactory both for thel above reason, and because it' is easily worked, and available at relatively low cost. For some purposes, it may be desirable to mix with the fibre and plastic compound amounts of finely divided solid material, such as cinders and the like to reduce the cost. v

In the production of the new shingles by the method of the invention; I employ a plurality of sheet forming devices or calenders, arranged in a line with each one delivering a sheet to the one next succeeding. To the first of these devices there is supplied a mixture of fibre and plastic in proper proportions to produce a' layer Waste paper, Wood fibre,

Novemof the desired physical characteristics to form one face of the finished prod ct, and a web of this material is sheeted Aout by the first calender and delivered to the one next in series. The second device operates on a mixture of fibre and plastic of different proportions from the first mixture and sheets out a web of `the second mixture, at the same time applying and uniting it to one face of the web first formed.v These sheeting-out operations are performed while the plastic material is relatively fluent's'o that the formation of the sheets and their union may be effected without difliculty. These steps are repeated in the later devices to build up a sheet of as many layers as maybe desired, though it is usually preferable to build up the final sheet of an uneven number of layers, the center layer or core containing a relatively small proportion of fibres to plastic, While the outer layers on each side thereof contain successively greater amounts of fibre until the facing sheets are reached, where the greatest amount of fibre is present. In the center layer or core, there may be present a substantial amount of ingredients cheaper than the iibre elsewhere used, examples oi.' such cheaper ingredients being waste paper,` cinders, clay, wood bre and the like.

In the production of shingles, a sheet is built up to the desired thickness by the devices described, and this sheet is then led to rotary molding devices which receive the sheet between r them and cooperate to vary the shape and thickness of selected portions thereof by the applicaltion `of pressure and then excise such formed portions from the sheet to form the nished product. 'Ihese cooperating drums have cooperating mold cavities in their faces by which the shaping operations are performed, and by the use of drums having cavities of different contour, products of different sizes and shapes, as desired, 95 may be readily formed from the sheet.

The roofing elements made in the manner described are preferably produced from a sheet having three or five layers, the central layer or core being more fiuent and less stiff than the w@ outer layers either by reason of including less 'fibre or solid material and more plastic, or plastic having a lower melt point. The outer layers include increased proportions of fibre to plastic,

the outermost layers including the greatest m5.

amount of libre so that they are firmer and more rigid than the layers between them. The shingles are nished by the application of granular surfacing material applied either to the finished shingles er, to the sheets before the m shingles are formed therefrom, the use of the greatest amounts of fibre inthe outermost layers preventing the complete submergence of the granules in the sheet when subjected to pressure.

For a better understanding of the invention,

reference may be had to the accompanying draw-y ings, in which: ,g

Fig. 1 is a view in side elevation diagrammatically illustrating apparatus for practicing the new method of producing the new shingles;

Fig. 2 is a similar view illustrating a modified form of` apparatus for)the same purpose;

Figs. 3 and 4 are sectional views of a sheet material and the novel roofing element produced therefrom; j

Figs. 5 and 6 are sectional views similar to Figs. 3 and 4 but showing a modification;

Figs..7 and 8 are plan views of. two forms of strip shingle which may beproduced by the new process.

Figs. 9 and 10 are plan views of two forms of individual shingles which may be produced by the new invention;

Figs. 11, 12, and 13 are edge views of three different types of shingler embodying the invention; and

Figs. 14 and 15 are sectional views of sheet material which may be used in making the `new shingles.

Referring now to the drawings, the sheet material illustrated in Figs. 3 and 5 is shown to consist of a plurality of layers united face to face.

The sheet shown in the first of these figures consists of five such layers, while the other sheet is made up of three layers. Ineach instance the sheet is coated on both faces and on one of these faces wear material such as crushed slate or the like is shown partially embedded in the coating. l

The materials of which the layers of this sheet material are made consist of fibre, and a plastic substance capable of hardening. Fibrous materials suitable for the purpose include asbestos, .cocoanut fibre, Wood fibre, bagasse, wool felt scrap and other similar products of that character. Various plastic substances may be used but I prefer to use those of a bituminous character, such as asphalt. The asphalt used is one having a melt point such that the asphalt is capable of withstanding solar heat. The sheet material may be made up of these ingredients in varying proportions and I prefer to build up a sheet material by joining together layers sheeted out of the mixtures of fibre and plastic, the proportions of these ingredients varying in the different layers which form a single sheet. In some instances 'it may be .desirable to add filling material, such as clay and waste paper, and for some purposes it isvsatisfactory to incorporate finely divided solid material, such as asbestos sand, infusorial earth, cinders, crushed rock, crushed slate and the like.

In preparing the sheet material, I prefer to employ a central layer or layers in Which-'there is a considerably lower amount of fibre present than in the outer layers which form the facings of the sheet, and a typical sheet such as that illustrated in Figure 3 may consist of five of these layers in which those designated 10 and 11 constituting the outer facing layers will contain up to about `50% of fibre and the remainder asphalt, While those designated 12 and 13 contain about 25% of fibre with the remainder asphalt, while the central layer or core 14 contains less and cheaper fibre, a filler, and the remainder asphalt. Preferablythe outer layers or facings are relaform what amounts to a protective jacket over the material which lies between them. Sheet material to be converted into roong elements 'by a shaping and cutting process, preferably includes asphalt of a melt point such that itwill remain plastic long enough to permitv the final shaping operations to be carried on with facility.

As an example of a mixture which is suitable for use in the central layer or core, I may employ asphalt, cindersand paper, a suitable mixture including pounds of paper, 90 pounds of cinders and 150 pounds of asphalt. The paper is first steamed and. pulped in a mixer,then mixed with the proper proportion of dry cinders and 'the mass ground in a suitable mill until the cinders are fairly fine and graded. This mixture is thenput through a dryer, preferably of the rotary steam-heated type, to remove moisture and then conveyed to a puglmixer where the proper amount ofasphalt is added.

This mixture of paper, cinders and asphalt affords numerous advantages when used as the central layer or core of a sheet to be converted into shingles, because the ingredients are of low cost, available in large quantities everywhere, and a shingle produced from them is semi-rigid, due to the presence of the cinders, is practically nonabsorbent, fairly light in weight, and a good iny sulator. In addition, such a shingle is resistant tral layer 15 contains the relatively lower proporl tion of fibre and the two facing layers 16 and 17 contain higher amounts of fibre and preferably up to about 50%. On both sheets coatings designated 18 and 19 are applied, these coatings being a waterproof substance, preferably asphalt of the desired melt point. In the coating 18 in Figure 3 there is partially embedded a layer of granules 20 which may be crushed slate, crushed rock and other similar products, ordinarily used to provide wear surfaces, while the opposite face of this sheet may have a coating of a non-stick material such as talc or the like applied over the coating. In the product shown in Figure 5, the granular material 20 is applied to the coating 19 and partially submerged therein, the granular material shown in these two figures being applied in differentl manners whereby in one iristance the granular material projects beyond the granules lie substantially flush with the coat- 'ing. The method by which the granular materials is applied to produce these different effects will be made clear hereafter. ,i

I n the production of the new sheet material, the plastic mixtures are preferably made up in advance of actual use, as for instance, bypulverizing the solid asphalt to the desired fineness and then mixing this asphalt powder with the desired amount of fibre. The mixture is then heated to render the asphalt fluent and this mixture conveyed to a device by which it may. be formed into a sheet. To build up a finished sheet, I utilize either the apparatus illustrated in Figure 1 or Figure 2.

In the apparatus shown Figure 1, there are erably three high ina stand. The rollsare power driven and the central and top rolls 22 and`24 preferably are cooled and operate at a higher speed of rotation than `the bottom roll 23 which is 5 heated. The rolls are spaced apart a distance which is dependent upon the thickness of the sheet to be formed thereby. The plastic mixture is delivered tothe stand by a conveyor generally designated 25 and of any suitable construction.

This plastic mixture is discharged into a feeding trough 26 which maintains a supply of the mixture in contact with the middle roll 22 and the bottom roll 23. These rolls rotate in the direction shown by the arrows and the action of the rolls is to draw plastic mixture from the supply through the space between the roll faces. The roll 22 carries withVl it a layer of the mixture designated 27, and this layer is carried around4 the face of the roll and passes between that roll and the upper roll 24. By reason of the rolls 22 and 24 being rotated at a higher speed than the roll 23 the action of the stand is to discharge the sheet 27 having a thickness determined by the spacing between the rolls 22 and 24,l and this sheet which constitutes one of the outside layers of the finished-product, is then led to the next stand.

In this stand there are cer tral and top cooled rolls moving at one speed of rotation and a bot- 30 tom heated roll moving at a slower speed. A mixture of the desired proportions is delivered by the conveyor 28 to the trough 29 and a sheet 30 is formed, which is carried around the middle roll 31 land applied to the under face of the sheet 27 as the two sheets pass between the middle roll 31 and the upper roll 32. 'This formation of a sheet and its application to the lower face of a built-up sheet previously formed is continued throughout the apparatus until in the apparatus \as shown in Figure 1 there is produced a final sheet 33 made up of five layers and similar to that shown in Figure 3. The character of the sheet will, of course, depend uponthe proportions of the b're and plastic material occurring in the several layers thereon, but preferably the sheet will consist of central layers in which there isga relatively small amount of fibre and two outer layers on each face in which the proportion of fibre to asphalt is relatively high. Also, itis preferable to form such a sheet with a core 14 somewhat thicker than the other layers and having a lower amount of bre, while the two outer layers 10 and 11 are relatively thin and contain a much larger amount of fibre. `The facing layers l may be of substantially uniform thickness.

` This sheet is capable of use for many purposes just as it emerges from the final stand of rolls but for roofing and other construction purposes,

. it is preferable to coat )its opposite faces with a 6G thin layer of asphalt. To apply this coating, there `is provided any suitable mechanism, such as a discharge nozzle 34 delivering asphalt in fluent condition upon the upper face of the sheet, the nozzle 34 having a plurality of lorifices to insure that the entire face of the sheet will be covered. Beyond the. nozzle 34 are placed rolls 35 and 36 preferably maintained atia suitable temperature to work the asphalt properly. The lower roll 36 enters a troughor vat 37 in 'which asphalt is maintained in fluent condition and this roll picks up asphalt and delivers it to the under face of the sheet 33. `The two rolls 35 and36 thus apply an asphaltic coating to the sheet emerging from the last stand of rolls. f

If the sheet is also to receive a facing of wear material, this can be accomplished by discharging granular material on the upper face thereof from the discharge mechanism 38, which may be of any ordinary type. The sheet with this granular layer thereon then passes beneath a hollow roll 39;

through which cooling water may flow, this roll serving to embed the granular material partially in the coating and also to give the coating an initial set. The sheet then passes around another roll 40 of similar construction, so arranged that the sheet reverses direction and moves with that surface uppermost which is coated but carries no granular material. To this stretch of material a non-stick material, such as talc may be applied, a suitable distributing mechanism 41 of any ordinary type being employed for that purpose. The sheet now passes around a cooling roll 42 which forces the talc into the coating to cornplete the application of the talc and givethe coating an initial set, and from the roll 42 Athe sheet passes to molding drums 43 and 44 to convert the sheet .into shingles.

These drums have cooperating mold cavities 45 and 46 in their faces, arranged if desired, so as to vary the thickness of the sheet at different points and to shape and consolidate the layers. These molding cavities are also dened by cutting edges of appropriate form which cooperate to cut the shaped portions from the sheet so that as the sheet passes through the molding drums individual roofing elements 47 are discharged therefrom upon a sloping platform 48.

In the apparatus as shown in Figure 2, the same principles of operation are emp1oyed, but the apparatus is modied'in certain respects to vary the type of coating that would be produced. In this apparatus, there are a plurality of stands of rolls 21 similar to those used in the type of apparatus previously described, and theplastic material is delivered to the first stand of rolls by a conveyor 25 discharging into a trough 26 which maintains a supply of material in contact with the middle roll 22 and the upper roll d24. This plastic material is sheeted out by the action of the rolls and travels around the face of the middlev roll in a manner previously described. ,Contacting with the outer surface of the sheet as it moves around the surface of the middle roll is a coating roll 49 resting lightly in contact with the sheet, and also contacting with a roll 50 which lies partially in a trough or vat 51 containing the coating material. The roll 50 picks up coating material from'the vat'51 and transfers it to the surface of the roll 49 which in turn'applies it to the surface of the sheet being carried around the surface of the roll 22.

Extending from end to end of the stands of rolls is an endless conveyor belt 52, which passes around guide rolls 53 and 5.4 at its ends. This conveyor belt may be a canvas webbing or a fine wire mesh and its upper stretch passes between the middle and lower rolls 22 and 23 of the several stands. As the first layer 27 is formed by the rolls df the first stand, this layer is carried along on the surface of the belt to the next stand, where another layer sheeted out of plastic and fibrous material 1s applied to its upper face. The sheet is built up in the manner previously described through the successive action of the stands of rolls and between each pair of rolls the sheet produced therein is supported on the surface of the endless belt. As previously described, a layer of coating material is applied to one surface of the sheet formed in the first stand of rolls by the roll This layer of granular material is carried along by the conveyor to a point Where the sheet and the conveyormove between'the rolls 22 and 23 and at that point the granular material is partially embedded in the coating by the action ofv the rolls. The coated layer with its outer fac-l ing of granular material passes through successive stands of rolls to receive and be united to the successive plastic layers formed by these devices. In this form of the apparatus, the top roll of each stand is preferably slow and heated While the two bottom rolls are preferably cooler and driven at a higher speed.

The sheet emerging from the last stand of rolls shown in Figure 2 consists of five layers made up of plastic and libre and it has a coating of asphalt on its under surface together with a layer of granular wear surfacing. The upper face of the sheet may now be finished by the application of a layer 'of coating material and for this purpose a pair of rolls 56, 57 are provided, the roll 56 running partially in a vat of coating material and delivering that material to the surface of the roll 57, which lies lightly in contact with the upper surface of the sheet. Beyond the roll 57 a nishing material may be applied if desired as, for example, talc, which may be delivered on the outer surface of the coating by a suitable distributing mechanism of any Well-known type generally'indicated at 58. Beyond this distributing mechanism, the sheet passes under a roll 59 Which smooths out the coating and embeds the talc or similar material therein, and the sheet may then be converted into shingle units by being delivered to the molding drums 43 and 44 previously referred to.

The molding drums have knife edges defining their mold cavities and the shape of these cavities determines the s'hape of the finished. product. In the manufacture of tapered shingles, molding drums are used which acton the sheet to shape selected portions thereof into individual units or shingles and then sever the sheet along the outline of the units. For example, the five layer sheet illustrated in Figure 3, when passed through the molding drums, may be converted into shingles of a cross-section similar to that shown in Figure 4, while shingles formed of the three layer sheet of Figure 5 have a crosssection similar to that shown in Figure 6. The sheet is delivered to the molding drums with the plastic ingredient still sufficiently fluent to permit the drums to perform the operations described. Also the plastic material used in the core is sufficiently plastic so that it will flow Linder the application of pressure by the drums and assume the desired tapering form, the outer layers to a greater extent preserving their origiincreases from the core outwardly toward either face.

By the use`4 of suitable molding drums, indi-v vidual shingles of rectangular form such as that designated 60 may be produced, or the individual shingles may have other shapes such as that numbered 61. Shingle 61 has its side edges converging toward the thick end and when this shingle 'is laid with others in the usual courses, the shingles contact laterally at their thin ends while at their thick ends, the side edges lie spaced apart in the ordinary manner.

The new shingles may also be made in the usual strip-shingle form 62 or in other forms such as that designated 63, in which the cutouts 64 are of Wedge-shape instead of having their sides parallel.

Instead of the tapering form shown in Figures 4 and 6, the shingles may be made in other shapes, such as those shown in Figures 11, 12, 13. Shingle 65 has one flat face 66 and the end edges 67 and 68 are inclined thereto. Shingle 69 has a uniform thickness for part of its length and a tapering thickness for the remainder, while shingle 70 is similar to shingle 69 except that the buttv end has a different type of edge.

In any of these shingles, the action of the cutting edges on th molding drums causes the outer layers of the s yeets to be forced into the central layers and to meet along the extreme edges of the shingles. As these outer layers are. highly fibrous, the finished product is one in which the more fluent inner layers are protected by the outer fibrous layers both along the faces of the shingles and along at least a pair of opposite edges thereof. Where the shingle is cut along all side edges from a sheet by the action of cooperating knife edges, the more fluent inner material will be completely enclosed over both faces and along all edges by the more fibrous outer layers, and these layers thus add strength to the shingles and prevent displacement of the core layers under pressure. The shingle therefore has what amounts to an encasing jacketv in which' a high proportion of fibre is present, but this is accomplished without using felt, paper, or similar felted fibrous material which-is preformed prior to its Iuse in the present apparatus. l

In the shingle shown in Figure 3, the granular material 20 has been applied by the apparatus shown in Figure 1. The sheet has rst been formed and then coated and a layer of granular material applied to the surface thereof. Since this granular material is not subjected to severe pressure after its application other than that applied by the molding drums, the granular material is only partially submerged in the coating and projects from the ysurface thereof. In the product shown in Figure 5, the granular mater' l has been applied, in accordance with the m hod shown in Figure 2, to the surface of the first layer produced during the formation thereof and this granular substance'has therefore been acted on by the rolls of a plurality of stands.

This layer is consequently submerged to a somewhat\greater extent than that shown in Figure 3, but the granules will not be completely submerged, although theirupper surfaces lie substantially flush with the layer of coating material over which they have been applied.

For some purposes, as in the production of relatively cheap shingles, it is permissible to form the shingles of sheet material such as that illustrated in Figures -14 and 15. In the material lla ' proof coating 76.

While I have described this sheet material as made up of a plurality of layers, which are illustrated in the drawings as distinct from one another, it is to be understood that in the finished product, these layers do not have any separate` existence but are united into. a unitary sheet in which there is no Well defined lines of demarkation. The plastic material used in the different layers is preferably of the same melting point, except in some instances 'a lower melt point may be used in the core or central layer, but in any event these sheets are united face to face in the apparatus While the plastic material is still somewhat fluent, so that a perfect union between layers is accomplished. In the drawings, these layers have been shown as separate and distinct for purposes of illustration, but in the finished product they merge together so that Ythe layers can be distinguished only by the varying amounts of bre present therein, and by somewhat different physical characteristics of these different layers resulting from such differences in fibre content. To produce a sheet material suitable for formation into shingles, I prefer to employ a sheet made up of an odd number of layers, with the outerlayers relatively thin and containing the higher proportions of fibre,

' but for a sheet material to be used Without further treatment as a roll roofing or siding material, various distribution of fibre and plastic may be employed, of which examples have been given.

This application is a division of my co-pending application Serial No. 291,638, led July 10, 1928.

1 claim: `l. A tapered shingle comprising a hardened/ plastic substance and unfelted fibre, the proportion of nbre to plastic substance varying from end to end of the shingle, with the greatest proportion of unfeltedV fibre being near the thin end.

2. A tapered shingle comprising hardened plastic substance and unfelted fibre, the 4shingle including facing layers of substantially uniform thickness and a core of tapering thickness from one end to the other, the layers and core being distinguishable by reason of the varying amounts of plastic substance and unfelted fibre therein.

3. A tapered shinglecomprising a pluralityof intimately bonded layers respectively formed of different mixtures of hardened plastic substance and unfelted fibre, the shingle` including a core relatively low in fibre content, and layers forming opposite faces of the shingle and containing a greater proportion of unfelted fibre than the core.

4. A tapered shingle comprising a core of tapering thickness from one end to the other, and including hardened plastic material and unfelted fibre, and a layer of substantially uniform thichiess oneach face of the core made up of hardened plastic material and unfelted fibre and distinguishable from the core in having a greater proportion of fibre.

5. A shingle comprising a core and a layer formed of a mixture of unfelted fibre and hard-4 ened plastic material on each face of the core.

6. A shingle comprising a core and a layer "f unfelted fibre ,and hardened plastic material on each face of the core, the layers meeting along4 of spaced tabs.

9. A shingle comprising a core including hardened plastic material and facing layers including an intimate mixture of hardened plastic material and unfelted fibre on opposite faces of the core. i

10. A shingle which comprises a central core of asphalt, cinders, and paper pulp, and outer facing layers lincluding unfelted fibrous material impregnated with asphalt.

11. A shingle which comprises ,a central core of plastic material, fibrous material and finely divided solids, and outer facing layers on the core made up of an intimate mixture of plastic material and unfelted fibrl/is material.

12. The method of producing roofing shingles which comprises, continuously forming under pressure a sheet composed of a plurality of superposed intimately bonded layers of dry mixtures of unfelted fibre and hardenable plastic material, at least one of the said layers having a smaller proportion of unfelted fibre to plastic material than the other layers, applying pressure to the sheet thereby forming a shingle tapering in thickness from one end thereof to the other, and cutting the thus-shaped shingle from the sheet.

13. The method of producing roofing shingles which comprises, forming under pressure a continuous sheet of a non-aqueous mixture containing unfelted fibre and a thermoplastic mapressure the resultant composite sheet" thus formed in a manner to adiust the thickness thereof to /form a tapered shingle. and cutting the said shingle from the sheet.

14. The method of producing roofing shingles Which comprises forming under pressure a continuous sheet made of a substantially dry mixture containing unfelted fibre and,I a uent thermoplastic material capable of hardening, the said mixture being of uniform preselected fibre content, sealing under pressure to each face of the said sheet, in the substantial absence of water, a layer made of a second intimate mixture containing unfelted fibre and a fluent thermoplastic material, thereby forming a composite structure having a middle core or layer which is more uent and less stiff than eachn of the pair of outer layers to which it is intimately bonded, shaping the composite structure, and cutting the shaped portions from the sheet.

15. A method of producing roofing elements which comprises uniting under pressure a sheet composed of/an intimate mixture of unfelted fibre and plastic material and a layer of, a mixture of,

unfelted bre` and plastic material having a lowerA ratio of unfelted bre to plastic material than that of the said sheet, applying a coating of surfacing material tol a face of the resultant cornposite sheet, and cutting elementsV of selected size from the sheet.

16. A method of producing roong elements which comprises uniting under pressure upon a sheet composed of an intimate mixture'of unfelted nbre and plastic material, a plastic layer of 'a mixture containing unfelted nbre and a plastic material capable of hardening, the plas- `tic layer having therein a lower ratio of unfelted bre to plastic material than the first-named layer, afxing a layer of surface material to at least one of the surfaces of the resultant com'- posite sheet, varying A the thickness of selected portions of the sheet, and cutting from the sheet the .said portions.` V

17. A method of producing roofing elements which comprises uniting under pressure upon a layer composed of an intimate mixture of unfelted bre and plastic material, a second layer of a mixtureof unfelted fibre and hardenable `plastic material, which second layerhas a lower percentageof unfelted fibre present therein than the first-named layer, then uniting under pressure -to thelast-named layer a third layer of a mixture of unfelted fibre and plastic material in approximately the same proportions as they are present in the first-named layer, shaping selected portions ofthe resulting composite sheet by the application of pressure and cutting the shaped portions from the" sheet.

18. The method of producing roong shingles which comprises, successively applying under pressure to a sheet composed of a drymixture of unfelted nbre and hardenable plastic material, a plurality of strata of dry mixtures of unfelted -bre and plastic material of regulated thickness, at least one of -the last-named dry mixtures having a smallerproportion of unfelted `fibre to plastic material than that of the layers unfelted nbre and hardenable plastic material;A

a plurality of strata of dry mixtures of unfelted fibre and plastic material of regulated thickness,

at least one of the last-named dry mixtures hav-- ing a smaller proportion of unfelted fibre to plastic material than that of the layers respectively superposed upon either side thereof, and apply- L ing pressure to the sheet thereby forming a shingle tapering in thickness from one end thereof to the other, and cutting the thus-shaped shingle from the sheet.

20. A shingle which comprises a pair of outer facing layers containing unfelted bre and plastic material in which the bre does not substantially exceed 50% of the material forming the layer,- subjacent layers each containing smaller percentages of bre to plastic material than that of the outer facing layers, and an inner core containing still smaller percentages of unfelted fibre together With plastic material and an inorganic ller.

21. A shingle which comprises a pair of outer facing layers containing unfelted nbre and plastic material 'in which the fibre is present in .not greater than 50% of the said layers, subjacent layers containing around 25% of unfelted fibre together with hardenable plastic material, and

an inner core containing a small amount of unfelted bre together with plastic material and an inorganic filler. f

22. A shingle which comprises a pair of outer facing layers containing unfelted bre and plastic material in substantial proportions, subjacent layers each containing smaller percentages of fibre to plastic material than that of the outer facing layers, land an inner core containing still smaller percentages of unfelted fibre together 'with plastic material and an inorganic ller, at

least one of the said outer facing layers being impregnated with a hardenable Water-proofing material.

23. A shingle which comprises a pair of outer facing layers containing unfelted fibre and plastic material in substantial proportions, subjacent layers each 'containing smaller percentages of bre to plastic material than that of the outer facing layers, and an inner core containing still smaller percentages of unfelted nbre together with plastic material andan inorganic filler, at least one of the said outer facing layers having an asphalt coating,V and a layer of Wear-resistant surfacing material partly submerged in the said asphalt coating. f

THOMAS ROBINSON. 

